Will it be your first Frontera? Check the exhaust properly and load it up to check rear springs neither of which I did and had to replace both.I was too excited to be sensible take someone sensible with you.Start it from cold before stating put your hand on the engine see if they warmed it up before you got there.Check the four wheel drive again I didnt just took the guys word that they had and when i did try it after I'd bought it there was a horrible shrieking noise i nearly died but it was only a cover plate over one of the axles in 4x4 mode and easily straightened out,Thank God. Hope this helps,Ive loved my 2.3 lwb but I,ve had anguish too.This is mainly because being self employed any time spent on the vehicle is time spent not producing. Don't know what else to suggest on a s.w.b.This site is full of helpful chaps.Good luck.